﻿using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace ConsoleApp4
{
    class SumUtils
    {
        public int Jishuan(int a,int b) 
        {
            return a + b;
        }
        public double Jishuan(double a,double b)
        {
            return a + b;
        }
        public string Jishuan(string a, string b)
        {
            return a+b;
        }
        public int Jishuan(int a)
        {
            int c = 0;
            for (int i = 0; i <=a; i++)
            {
                c = c + i;
            }
            return c;
        }
        public void mianji(double r) 
        {
            Console.WriteLine($"圆的面积为{r*r*3.14}");
        }
    }
}
